Datasheet

LTC3714
17
3714f
applicaTions inForMaTion
INTV
CC
Regulator
An internal P-channel low dropout regulator produces the
5V supply that powers the drivers and internal circuitry
within the LTC3714. The INTV
CC
pin can supply up to 50mA
RMS and must be bypassed to ground with a minimum of
4.7µF tantalum or other low ESR capacitor. Good bypassing
is necessary to supply the high transient currents required
by the MOSFET gate drivers. Applications using large
MOSFETs with a high input voltage and high frequency of
operation may cause the LTC3714 to exceed its maximum
junction temperature rating or RMS current rating. Most
of the supply current drives the MOSFET gates unless
an external EXTV
CC
source is used. In continuous mode
operation, this current is I
GATECHG
= f(Q
g(TOP)
+ Q
g(BOT)
).
The junction temperature can be estimated from the equa-
tions given in Note 2 of the Electrical Characteristics. For
example, the LTC3714EG is limited to less than 14mA
from a 30V supply:
T
J
= 70°C + (14mA)(30V)(130°C/W) = 125°C
For larger currents, consider using an external supply
with the EXTV
CC
pin.
Table 1. VID Output Voltage Programming
VID4 VID3 VID2 VID1 VID0 V
OUT
(V)
0 0 0 0 0 1.75V
0 0 0 0 1 1.70V
0 0 0 1 0 1.65V
0 0 0 1 1 1.60V
0 0 1 0 0 1.55V
0 0 1 0 1 1.50V
0 0 1 1 0 1.45V
0 0 1 1 1 1.40V
0 1 0 0 0 1.35V
0 1 0 0 1 1.30V
0 1 0 1 0 1.25V
0 1 0 1 1 1.20V
0 1 1 0 0 1.15V
0 1 1 0 1 1.10V
0 1 1 1 0 1.05V
0 1 1 1 1 1.00V
1 0 0 0 0 0.975V
1 0 0 0 1 0.950V
1 0 0 1 0 0.925V
1 0 0 1 1 0.900V
1 0 1 0 0 0.875V
1 0 1 0 1 0.850V
1 0 1 1 0 0.825V
1 0 1 1 1 0.800V
1 1 0 0 0 0.775V
1 1 0 0 1 0.750V
1 1 0 1 0 0.725V
1 1 0 1 1 0.700V
1 1 1 0 0 0.675V
1 1 1 0 1 0.650V
1 1 1 1 0 0.625V
1 1 1 1 1 0.600V